Broken Images on my web browsers including Safari

Essentially the problem is that my Mac is not displaying certain images on my company's website (gatewayhd.com). I've tried several different browsers (Safari, Firefox, Chrome) but they all have some version of a broken image in the place where I know the image is. I can see them just fine on any of my PCs both at work and at home. I've tried taking my Mac home and to other internet hotspots thinking maybe it was some block my over-protective-not-Mac-friendly IT department put on our network or wifi. But it doesn't work from home either. The other thing I've noticed is that the only images affected are images that are hosted on my company's internal server. All images that I put on the site that are hosted by a third party (Picasa, Flickr, Image Managers of various Web Editors, Facebook, etc) show up just fine for me. Is it just my Mac or is it everyone's? Is it an update or plugin that needs to be ran? Is it some goofy setting I can't seem to get right? Most importantly I was wondering if the issue had something to do with me or if potentially more people would be affected by this? I design the website for the company and I don't want to be hosting images internally if they can't be viewed on Mac's web browsers.

Please help!